Ethics are a compass for ourselves, not to judge others, yet many Buddhists feel confident they can —and even should— criticise Aung San Suu Kyi recently.

Sure, we might discern behaviours (by others) that seem unwholesome, but then it's about us taking responsibility to inspire a change towards the wholesome, not about condemning the 'faulty' actor.

« a monk who wishes to reprove another should first establish five things in himself. What five? (1) He should consider: ‘I will speak at a proper time, not at an improper time; (2) I will speak truthfully, not falsely; (3) I will speak gently, not harshly; (4) I will speak in a beneficial way, not in a harmful way; (5) I will speak with a mind of loving-kindness, not while harboring hatred.’ A monk who wishes to reprove another should first establish these five things in himself… » — AN 5.167

Fundamentally, it is unclear that Aung San Suu Kyi's behaviour was ‘ethical' out of appropriateness and wisdom, during her peaceful resistance against a dictature… or if she was just stubborn, and clinging to a particular view of how the world 'should' be. Sometimes, righteous ignorance and wisdom appear the same to outsiders, often simply because we cannot read the mind of others or their intentions.
So we need to question the projections we put on the ‘earlier' political career of Aung San Suu Kyi, and not just whether the Nobel Peace prize laureate has changed.
And even if we think she recently lost it, we might need to reflect on the responsibility we bear in this (e.g. maybe we just failed at getting her out of confinement fast enough to protect her sanity…). It’d be too easy to have unrealistic expectations on her, otherwise, while avoiding to look in the mirror.

But if we care of Buddhist ethics, it seems weird to mention Aung San Suu Kyi, but not Venerable Wirathu! It’s like blaming the witness of an attack, for not intervening (or not enough), but not blaming the attacker himself first and foremost. And a lot of recent positions, declarations, articles, do exactly that: they take the violence of Wirathu for granted, therefore ignore it, while they criticise Aung San Suu Kyi.

And if Venerable Wirathu teaches us something, it’s very much that Buddhism is not a magical, fail-safe antidote against racism or discrimination. No more than Theravāda Buddhism prevented dictatures… People do not become enlightened merely by wearing robes, or by staying in the order long enough to gain “venerable" titles.

There’s no reason why Aung San Suu Kyi should be expected to be faultless…
hence the true question: how can we support her, instead of merely expecting her to behave the way we think she should?

Thinking "of course she should intervene, say something…" is too easy. There’s virtually no situation in which the Dharma would suggest an “of course”: reality is ineffable and the context is richer than black&white caricatures of it.
It might seem weird, for example, to call international Buddhist leaders to pressure Aung San Suu Kyi, who is not a religious figure, rather than pressuring the monks leading the mob. And Aung San Suu Kyi is a Theravāda practitioner, so Theravāda luminaries are more likely to influence her than e.g. secular Westerners (no offence intended)…
But even if we accept a need to speak up as "evident", she has to find a way to speak out without making things worse, without provoking ignorant ‘Buddhists’ to deepen and hasten their oppression (before the state prevents it), it’s easy to assert “she should” from afar, it’s harder to actually propose a speech that would actually help. Merely stating “she should try” is an attempt to push our own responsibility on her; the question for Buddhist practitioners is more akin to “given the situation, what can I do ? what words may we suggest, which she would not have thought about already, and which would be constructive?”.

If we just wash our hands and put all the blame on Aung San Suu Kyi here, then we're still entangled in ignorantly believing our views and preferences about "how the world should be" (instead of "seeing how the world is") and then suffering when we realise the world (incl. Aung San Suu Kyi) does not comply to our wishes.